In recent years, cloth having high functionality has been developed and use of such cloth for interior material in the automobile and building industries is increasing. High functional cloth, that is cloth having three-dimensional patterns, is cloth having an uneven surface and is attracting attention as high quality cloth having three-dimensional texture. Particularly, demands for the cloth as material for automobile seats and walls are increasing largely.
As a method for forming such three-dimensional patterns on cloth, conventionally, the method of physically forming uneven areas and the method of chemically forming uneven areas have been studied and employed.
Examples of the physical method are embossing, in which embossing is conducted by contact pressure of an engraving roll under heating at a high temperature, and schreinerizing. However, because the cloth is inserted between heated rolls under heavy pressure, the texture becomes extremely hard and the cloth becomes extremely flat. Also, there is the problem that metal luster due to the heat roll and thermal discoloring may occur.
An example of the chemical method is the method of treating with textile printing paste, in which a chemical that shrinks or reduces the weight of fiber is mixed when textile printing, as described in JP-B-47-23709. When a naphthol derivative is used as the chemical, there is the problem that the chemical tends to be applied unevenly, as the naphthol derivative has difficulty dissolving in water. When amine or an alkali metal hydroxide is used, there are the problems that foul odor is generated and harmful and hazardous effects are high. In order to solve these problems, JP-A-2000-96439 suggests mixing guanidine carbonate in textile printing paste as the chemical. Although there is the problem that the paste that is used must have alkali resistance, thereby limiting the type of paste that can be used, this method seems to be excellent in terms of reproducibility of uneven areas, environment and safety.
However, in all of the methods described above, patterns of the heat roll or textile printing screen must be formed first and there is the problem that accommodating for processing of small numbers is extremely difficult, in terms of time and cost. Also, because the textile printing paste containing the chemical has high viscosity, permeability to cloth is low and in the case that plush fabric having long pile length is used, the chemical does not reach the end of the pile and unevenness tends to be insufficient.
In order to solve such problems, in recent years, the method of forming three-dimensional patterns by applying a fiber shrinking agent to cloth by ink jet printing is attracting attention.
According to the ink jet printing method, patterns do not need to be formed on a heat roll or a textile printing screen and also, ink jet printing is excellent from economical and safety viewpoints, as the chemical can be applied to the cloth by spraying to only the necessary areas in the necessary amount. Furthermore, the obtained three-dimensional pattern is an extremely elaborate pattern that could not be obtained by the conventional method and therefore, is extremely useful.
An example of the method for forming three-dimensional patterns by ink jet printing is the method of shrinking pile by spraying a fiber shrinking agent from a nozzle, as described in JP-A-10-298863. In the above method, ink having high viscosity of 100 to 200 cps is used, but because the usual ink jet printing apparatus is for ink having low viscosity of approximately 1 to 10 cps, a new printing apparatus for high viscosity ink becomes necessary. Also, because the ink has high viscosity, clogging of the nozzle tends to occur. Furthermore, because permeability of the fiber shrinking agent to cloth is low, in the case that plush fabric having long pile length is used, the chemical does not reach the end of the pile and unevenness tends to be insufficient.
Furthermore, because the ink is transparent, the discharge conditions of the ink cannot be detected or examined and there is the problem that detection of discharge failure in the production line is delayed. Consequently, adding a colorant to the ink has been considered, but when a colorant is merely added to a fiber shrinking agent, coagulation and precipitation tend to occur and ultimately, discharge failure is caused.
As described above, the ink jet printing method is considered to be extremely useful as a method of forming three-dimensional patterns on cloth, but an ink for forming three-dimensional patterns, which can form clear patterns by unevenness and can be used for mass production, has not yet been found.